I started my first site in 1994, mainly as a way to teach myself the then-exotic skill of HTML coding, and fell into reporting on Mac games shortly thereafter, when I figured out I could attract readers by writing about what I knew.

In the nearly two decades I’ve been doing it, I’ve seen huge changes — from shareware games downloaded via BBS services and from FTP archives on the Internet to $70 boxes containing games on floppy discs. From hybrid CD-ROMs containing both Mac and PC games to DVDs. I’ve seen Mac games sold on on the shelves of big-box retailers that don’t exist anymore. I’ve heard plenty of complaints from Mac gamers who couldn’t find games for their computers. I’ve seen the Apple retail stores rise up, offering Mac gamers a great way to buy software. And I’ve seen that go away, as Apple decided iPhone accessories were a better use for that space.

Commercial Mac game releases never died off, but they definitely slid into the background for a while. Two key events changed that: Valve’s decision to bring Steam to the Macintosh, and Apple’s decision to launch the Mac App Store. Since then, there’s been a resurgence of games on the platform.

A fair number of the games are casual titles aimed at Mac users who don’t self-identify as gamers but might be interested in games that pique their interest — word games, puzzlers, and clones of other popular games. And that goes for Steam as well as the Mac App Store. But there’s a lot of great software that, in another era, we’d have to go to an Apple Store or Comp USA to buy — titles from leading game publishers and indies alike.

Steam and the Mac App Store are cut from similar cloth — they both enable Mac users to easily download games, but there are a few key differences that worry me. Both of them are staking a claim to exclusive territory that’s creating some balkanization for the Mac gaming landscape. I don’t think is helpful or conducive to creating a healthy Mac game market.

Valve has created a thriving ecosystem in Steam — it’s not just a place to buy and download games, it’s also a place to play them. You can join a clan of like-minded gamers to team up with for multiplayer adventures. You can chat with them in real-time. And you can unlock achievements within the game by completing various goals.

Many of the same games you can buy on Steam you can buy on the Mac App Store. You can also get them through other gaming services, or download them directly from the publisher’s web site. And this is where things get tricky.

All of those features designed to enhance and simplify the multiplayer experience and reward players for playing through their games are entirely service-dependent. Steam games use Steam services to communicate. Mac App Store games are increasingly depend on Apple’s Game Center technology, which doesn’t talk to Steam games (or anyone else, for that matter). And Game Center is available as a Mac App Store exclusive. Mac games purchased outside of those ecosystems need some other way to communicate. Many of them resort to plugging in support for a third-party service like GameRanger to accomplish multiplayer game connections.

This adds a layer of complexity to the Mac game purchasing process — do I buy the game I want directly from the publisher, through a service like Mac Game Store or GamersGate, or do I go to Steam or the Mac App Store?

Some of that is driven by price; some of it is driven by accessibility, but I’ve spoken to gamers who have regretted their purchases because they didn’t realize they’d be incapable of playing with their friends on another service. That’s going to continue to happen as Mac gamer’s choices expand. And sometimes, choice causes confusion and leads to disappointment.

The Mac game market is more robust than it has been in years, and if you have a decently fast Internet connection and are willing to sign up for one (or more) of these services, you have a wealth of options to choose from. Just make sure the one you choose is the right one for your specific need, or you might be stuck with a game that’s less than it could have been.

Bio: Peter Cohen has amassed more than two decades of professional experience in the Apple marketplace, with a career spanning tech support, IT, and since 1994, online news. @flargh